View Full Version : Light 45-70 loads with IMR4198

03-08-2018, 11:54 PM
Is anyone using Trapdoor load data for 45-70 using IMR4198 in their Marlin 1895? I cast Lee 457-340-F bullets and used 35 grains of IMR4198. Was getting incosistent ignition and had a bullet get stuck in the barrel. This was with my first 5 loads. After this I gave the next 5 loads a heavier crimp and made sure the powder was against the primer. These 5 gave no issues. The first 5 also left real dirty cases on the outside. The next 5 with the heavier crimp and attention to the powder, I had clean cases after firing. Is this normal with the lighter loads? Should I just step up to the 1895 load data? Was trying to make some light plinker loads.

03-09-2018, 07:38 AM
I use 30 gr. IMR4198 with 385 gr HP and a dacron filler in my Trapdoor with no issues.
I think this load running black powder pressures....dale

03-09-2018, 12:33 PM
For lite loads I like unique. 13 gr under 457193 405 gr boolit. 1k to 1100 fps, very mild recoil. My Uberti sharps with 28 in barrel is great with this load. My Uberti trapdoor has a 32 in barrel and doesnt like the same load. It is leading the last 12 or so in of barrel. I seems to be running out of lube in the last of the bbl. What dia are your 340 gr bullets? My 340 Lee mold is dropping 457 dia bullets and rifles like 459 dia. I am going to try pcing bullets to increase dia and solve lube problem in trapdoor.

03-10-2018, 11:17 AM
I use 29-30 gr IMR 4198 with dacron in my 1895 CB under a 330 Gould boolit. Shoots great, has accounted for several deer, many paper holes etc. Mild recoil, noise level. Even tho hollow point COWW, will shoot thru both sides of a propane tank at 100 yds.

Larry Gibson
03-11-2018, 07:30 AM
You might back off to 30 gr and use a Dacron filler. Work back up to the TD velocity you want.

03-11-2018, 09:11 AM
I tried the 340 gr. bullet cast from the Lee mould years ago. I got good accuracy using 34 grs. IMR4198 for a muzzle velocity of 1420 from a Marlin lever action. Alloy was approximately Lyman #2. I've also had good results with IMR4198 using the 400 grain gas checked bullet (RCBS mould, Lyman #2) in several rifles. The 420 grain plain base from Lyman's #457193 cast of wheelweights has also done well using 31 grs. 4198 for a muzzle velocity of around 1325 fps.

I haven't looked at the article in a long time, but Ken Waters did a lengthy .45-70 evaluation for PET LOADS and I think he also had good results using similar .45-70 loads. I don't use fillers nor do I crimp unless absolutely necessary. Loads burn clean. CCI primers were used in all my loads.

The only bullet I use anymore in my .45-70s is cast from Lyman's #457122, the 330 gr. HP cast of WW alloy. It's at least as accurate as any of the others I've tried but shoots best with 28 grs. SR4759 for a muzzle velocity of around 1500 fps. I did not have great success from an accuracy perspective with this bullet and IMR4198.

03-11-2018, 09:46 AM
28 gr of 4198 with the cast 405 rnfp gives me about 1230 fps from my 1884 TD . Great load, easy on the shoulder.

03-11-2018, 10:45 PM
So, plinking round: Do about 15-16 grn of trailboss - that will shoot straight and won't stick in the barrel.
For a light 4198 in a 405 grn, do about 40-42 grn. When you get to 48 or so grn, it gets a little heavy on the shoulder. I think max is around 50 grn... Don't go over about 45 grn with a plain base boolit.

03-15-2018, 10:46 PM
thanks for all the advice, seems like dacron may be something to try with the light loads then. to those of you using dacron, did you experience inconsistent ignition without dacron and light 4198 charges?

03-16-2018, 10:35 AM
I agree with 44Blam Man, Trail Boss is the smokeless powder for 45-70 plinking rounds. I use 13.0 grains behind a Lyman 457193 405 grain bullet. Accuracy is very good and recoil is such that any of the Boy Scouts in Troop 4 here in Ogden, Utah can manage it in a full size 1884 Trapdoor . This load also shoots well in my 1886 Winchester lever gun. Back to the original question...I buy IMR4198 by the 8 lb. keg. This is my favorite smokeless powder for cast boolits. I have to agree with Larry Gibson too. I think I would start with 30 grains of IMR 4198 and work up from there. Since many of the cast boolits from .45 molds are not gas check designs pushing them too fast will probably cause you grief.

03-16-2018, 10:50 AM

I have never used a filler in any cartridge that wasn't Black Powder. I have never had ignition problems even with light loads of Unique in large rifle cartridges. I use WLR primers when I can. This said I have found Larry Gibson's advice to always be good. In theory the fiber keeps the lighter load back against the primer for better ignition. Since the 45-70 case has substantially more volume than my Krag cases it would make sense that you would try this approach. The problem seem to be that you can't get this material from ANY reloading supply store. It seem you need to find it by either buying a spare pillow at Walmart or tearing apart an old stuffed animal.

Rick Hodges
03-16-2018, 10:54 AM
I tried H-4198 with a MM 385gr boolit and 300 gr. jword. I didn't like it. It recoiled excessive, felt very "Hot" with loud muzzle blast without the chronograph showing velocities near what were suggested in load manuals. I'm not sure what the problem was but I won't use it at all in my 1895. It and IMR version were my go to powders in .222 R and I will relegate it to those type small bore small case cartridges.

03-16-2018, 06:31 PM
+1 on TrailBoss. I shoot the following reduced loads on my H& Handy Rifle (45-70), and my Marlin Lever Action (45-70):

- Accurate 46-355gr, GC - 15.0gr and 16.0gr TrailBoss

- Accurate 46-300 DC, GC - 16gr TrailBoss

- NOE 185gr Collar Button, Plain Base, 11gr - 15gr TrailBoss

My next load is using the NOE SC460-425-RF 4 cavity GC, which I plan on making it into a subsonic hog hunting round, also will a near max load of TrailBoss :)

Here are some photos of the 355gr:


And some pictures of the Collar Button:


Here is my new 425gr, and next to my much smaller 308 cal 180gr: